Machine for packaging cartons



May 23, 1961 H. w. WILSON ET Al.

MACHINE FOR PACKAGING CARTONS Original Filed April 29, 1957 3 Sheets-Sheet l HARRY 14 W/ZM/v c/wm/v 0 B W k.

May 23, 1961 H. W. WILSON ET AL MACHINE FOR PACKAGING CARTONS Original Filed April 29, 1957 M0 i Z Er388 5 Sheets-Sheet 5 INVENTORS HARRY vV. WILSON CLINTON 1.. DORA/BUSH MACHINE FOR PACKAGING CARTONS W. Wilson, Millbrae, and ClintonL. 'Dornbush, Palo Alto, Calif., assignors to Royal Container Co., San Francisco, Calif., a corporation of California Original application Apr. 29, 1957, Ser. No. 655,774,

now Patent No. 2,947,125, dated Aug. 2, 1960. Divided and this application Oct. 17, 1958, Ser. No. 771,693

3 Claims. (Cl. 214-6) This invention relates to a novel unloading device, used in connection with apparatus for packaging collapsed cartons.

This application is a division of application Serial The inconvenience of these prior-art packaging methods has been overcome by an invention by Harry W. Wilson, described in his application Serial No. 592,185, filed June 18, 1956, for a self-palletized package and in his continuation-impart application, Serial No. 651,615, filed April 9, 1957. In that invention the bale is formed by strapping together a suflicient number of cartons to make, when compressed and secured together, a bundle or bale one-half the width of a truck or rail car. The finished self-palletized bale is characterized by resting on a pair of runners that formed an integral part of the package, being held to the package by the same steel straps that hold the bale together. Also, the self-palletized bale is characterized by the fact that the cartons stand on edge and are held under pressure during strapping so that all the air is squeezed out and the surfaces made equiplanar. All this is explained in the applications referred to. The self-palletized bale is very stable and can support additional layers of unpalletized bales, for handling several layers as a unit, and the units can be stacked on top of each other in warehouses. A relatively inexpensive, unitary, and highly efficient package results. The pallet and bale are the same size; so the problems in warehousing, storage and transportation are solved. The low cost of materials makes unnecessary the return of pallets and eliminates the bookkeeping that goes with returnable pallets.

This new bale has another extraordinary feature: it makes it possible to provide self-palletized bales even from cartons that are too small to be handled in a single stack by fork-lift trucks, i.e. where there is not enough room to provide entry space for the forks, which are usually about 28" to 32" apart. This important result is accomplished by a novel double stack of the smaller cartons, joined only by locking sheets (or cap sheets, as they are sometimes called) that are strapped into the bale. By pitting against each other, through the locking sheets, those forces that tend to cause the bale to come apart, the bale can be held together by flanged locking sheets of corrugated paper. The high shear or tensile strength of sheet material when subjected to stretching, is availed of in a novel manner fully explained in the aboveidentified continuation-in-part application.

ts tent ice - In any event, when this improved bale was first introduced, the stacking had to be done by hand and the entire operation had to be done on a batch-basis, usually by two men. It involved a lot of hard work and manual labor. It was difiicult for hand labor in the packaging stage to keep up with modern carton production machines, which can produce a hundred thousand k.d.f. cartons in an eight-hour day.

The parent application, Serial Number 655,774, and co-pending application Serial Number 696,304, filed October 21, 1957, solve the packaging problem by, respectively, apparatus and methods which greatly simplify the packaging of k.d.f. boxes into self-pailletized bales, or other convenient types of packages.

An object of the invention is to provide an automatic unloading device, which automatically organizes the packages into groups of self-palletized bales embodying four or more large stacks, two stacks on a bottom layer and two or more on one or more upper layers all supported on one set of boards, so as to save materials, especially cap sheets and pallet boards.

Other objects and advantages of the invention will appear from the following description of a preferred embodiment. y

In the drawings:

Fig. 1 is a view in side elevation of an unloader embodying the principles of the invention.

Fig. 2 is a view in section taken along the line 2-2 in Fig. 1, and showing the bale unloader in three positions, the unloader being shown in solid lines in its normal, unftipped position, and in broken lines in two of its tipping postions; one where it tips to receive the first layer of packages, and another where it empties a two-layer unit of packaged cartons onto a roller conveyor.

Fig. 3 is a top plan view of a portion of the unloading unit, with some parts cut away, shown as looking down on Fig. 2.

Fig. 4 is an electrical circuit diagram of the device;

The machine shown in the drawings is often used as part of a multi-stage device described in the parent application Serial Number 655,774, each stage of which is adapted to perform one or more steps and is related to the other stages. In general, small stacks of k.d.f. cartons are placed on an introductory conveyor, which leads into a stacking device, where the small stacks, usually about 25 k.d.f. cartonseach, are made into large stacks E many times as big, such as stacks of about to'ZOQ cartons. The large stack E is then advanced by an ejector into the next stage of operation, which may be called an accumulator. I

In the accumulator a first large stack E is held until a second similar stack E arrives. In those bales that are to be self-palletized, a single oversize bottom cap or locking sheet H may then be applied beneath the two stacks, E and E For most operations, it is advisable to add the cap sheet manually, though it may be added by automatic machinery.

When the operator has the bottom cap sheet H in place (if one is used) and at the proper time to advance the two stacks E and E he presses a button that send them into a press I while folding up the protruding sides of the cap sheet H to provide a pair of stabilizing flanges whose importance is explained in thereferred-to applications. At the press I, the stacks E and B are compressed tightly together and baled with steel strapping (or baling wire, if preferred). In those instances where a self-palletized package is to be made, an additional locking sheet K and two pallet strips L are applied, and in all instances bumper strips M are applied, before the strap J, to protect the edges where the Wire or strap J turns a corner. The baled and self-palletized package N is then ,advanced along a conveyor 0 to the unloading device P of this invention, where the bale N (which is purposely manufactured on-end) is tipped way from the conveyor and, preferably after a second or third or fourth layer of bales is received, is unloaded to an unloading conveyor'Q. f p

v 'The unloading device P is shown in Fig 1 next to a pressil. i V i w A relay 140 controls a motor 141 that drives horizontal rollers 142 in the press I, through gears 143, 144and 145 and chains 146 and 147; so they rotatef aiid convey the single-packs E and E along in the press I. The packs E and E continue moving until the forward edge of the pack E reaches an adjustable vertieal st0p'150 and engages and opens a normally closed switch 151; thereby stopping the motor 141. 'i It may be noted that the stop gate 150 preferably includes a telescopic frame that fcan 'be tall enough to contact the entire height of the sthek 1E," end yet will telescope inside'itself when the pres'sl closes, softhat it will not be damaged upon closure of the press. I The press I has a strong mainframe 155 into which the packs E and B are carried by the rollers142, and the frame 155 is equipped with a press bed 156, including a series of strong steel horizontal beams 157- extending transversely'acrbss the frame 155. The rollers 142 are mounte'd'on a separate frame 160 whose links 161 are pivoted to the frame 160 at 162 and are pivoted at 163 to the press frame 155, so that the rollers 142 may be raised above thebed' 156. for driving the package or may be lowered below it during the pressing, baling and strapping. The raising and loweringis accomplished by a cylinder 164 'whosepiston 165 has its outer end 166 pivoted'to a crank arm 167, which in turn is connected directly to one link 161 and indirectly by bars 167:: to the other l in k 161.

The frame 169 may be lifted by air, whose entry to the cylinder 164 is controlled by a solenoid valve 168a. The solenoid 16$ may be de-energized by'a manual switch 169 to" drop the rollers 142 by releasing air from the cylinder 164 The switch 169 may, if desired, be tied intq and be made a part of the stop switch 151.

The. vertically extending stop gate 150 straightens the packs E and E by virtue of their forward inertia; so the stacks are very straight after they hit the gate 150. V The pressl includes a heavy horizontal upper platen 170' which is mounted for vertical movement with respect to the frame 155 and bed 156 by means of four racks 171 on the vertieal members 172. of the frarne 155 and four pinions 173 on two axles 174, both axles being journaled in respective brackets on the platen 170,

The vertical movement of the platen 170 is powered preferably by a pair (or one or more) of hydraulic cylinders 180, 181with pistons 18 2 183; the cylinders 180, 181 being secured rigidly to the frame 155 and the pistons 182, 183 being rigidly secured to the platen 170, A hydraulic pump 185 controls the supply of liquid to the cylinders 18!}, 181, its lever 18;6 being manually held in one direction to lower the platen 170 and in'the other direction to raise the platen 17%}. Before lowering the platen 170'on a package requiring an upper locking or cap sheet K, the locking sheet K is first inserted. The operator makes sure that the locking sheet K is properly positioned, if he wants a locking sheet K, and then moves the lever 186 to lower the platen 170.

The bed 156 preferably has a pair of cross-members 190 set lower than the remaining bed members and provided with a pair of recessed channels 191, andcrossmembers 192 of the platen 170 are set in recesses in the platen 170 and are likewise provided with recessed chan: nels 193. In the recess or groove provided by the members 1 90 and 192, the bumper strips M may be inserted. Preferably, the operator places the lower bumper strips Min the channel-like area provided by the cross-member 19(l beforethe frame 1691s lowered and before moving the lever lsstblow'er the platen 170. The upper bumper strips M are preferably inserted in the groove provided by the member 192 as the press is closed or when it is partially closed. After the bumper strips M have been inserted and lie in their proper place, the baling straps 1 may be threaded through grooves 191 and 193 respectively, in the cross-members 190 and 192. The strap J is passed around the package N and its ends joined together by a machine conventional for that operation. Where palletizing is to be used, a couple of pallet rails L, preferably with strap-receiving grooves 157, are inserted beneath the band I While it is being threaded around the package, preferably on the same side of the machine as the tipper P, which may be on the opposite side from the strapper. At this point, the single packs E and E have become an integrated, self-palletized unit N held together by cap sheets H and K.

The upper platen 170 may now be raised by moving the lever 186 to reverse the pressure in the cylinders 180 and 181. On reaching the top of its travel, the platen 170 closes an electrical switch 200 which actuates a holding relay 261 that energizes a solenoid'202. The valve 202a sends air into the right hand port 203 (Fig. l) of a stop gate cylinder 204 which is pivotally secured to the press frame 155, moving its piston 205 outwardly (to the left in Fig. 1). The piston 205 is connected by a pivotal connection 266 to a crank 207, which in turn is rigidly connected to a-vertical pivot member 210 of the vertical stop gate 150. Movement of the piston 205 therefore rotates the stop gate 150 outwardly on its hinge 211 until its main column 212 (connected to the pivot member 210 by horizontal member 213) is entirely to one side of the press I, where it no longer presents an obstruction to the forward movement of the unitized package N.

A manual switch 215 (preferably manual, though it may be automatically actuated by the full opening of the gate 150) is then pressed. The switch 215 actuates the relay for the motor 141. When the motor 141 is actuated, the rollers 142 start to revolve, and at the same time the solenoid 168 is energized, pressurizing the cylinder 164 so that the frame 160 is lifted. When the rollers 14?. engage the lower cap sheet H, they pick up the package N and convey it to a belt 216, which is driven by the'shaft 217 of one of the rollers 142 (and so by the motor 141). The belt 216 in turn conveys the package N to the conveyor 0, preferably but not necessarily of the gravity. type.

The conveyor 0 hasa frame 220 in which rollers 221 are mounted'for free rotation. The rollers 221 are set on an incline; so gravity causes the package N to slide down over them until it hits a generally vertical stop barrier 222, where it engages and moves a switch 223. It will be noted that the barrier 222 also includes a frame 224 supporting rollers 225 for free rotation generally, on vertical axes.

The tipping device P is mounted adjacent the conveyor 0 and comprises a generally L-shaped frame 230 rotatably mounted on a shaft 231 which is journaled in brackets 232 on a portion 233 of the frame 220. The normally horizontal portion 234 of the tipper frame 239 has rearwardly mounted, freely rotatable rollers 235 and forwardly projecting fingers 236 which lie in between rollers 229 and carry small, freely rotatable rollers 237, which normally lie below the uppersurfaces of the rollers 221. The normally vertical portion 240 of the frame 230 also supports freely rotatable rollers 241 on horizontal axes.

When the switch 223 is moved by engagement. of the package N, the relay 201 is de-energized, de-energizing the solenoid 202 and thereby closing the stop gate in the press I (as explained in the parent application, Serial Number 655,774) so that a new set of stacks can be brought from the accumulator into the press I by manually closinga switch (not shown). An interlock of circuits at the switch 223 prevents this action heretofore.

Engagement of the switch 223-by the package. N.. also actuates a holding relay 243 which, in turn, energizes a solenoid 244 whose valve 244a sends fluid into a cylinder 245 (preferably hydraulic) at the left hand port 246 (Fig. 2) to pull its piston 247 in, to the right in Fig. 2. The piston 247 is pivotally connected to a frame crank 248 so this movement rotates the frame 230 counterclockwise in Fig. 2. As rotation begins, the fingers 236 pick up the package N and begin lifting it olf the rollers 221. After only a few degrees of tipping, the package N begins to slide along the rollers 237 and 235 and finally slides up against the rollers 241 of the vertical frame portion 248. In the meantime, and before the package N reaches the rollers 241, a cam 250 secured to the tipper frame portion 234 loses contact with a follower 251, which is supported by the frame 228, thereby opening a switch 252, de-actuating the relay 243 and de-energizing the solenoid 244. This sends fluid into the right hand port 253 of the cylinder 245 and the tipper frame 230 is then rotated (clockwise in Fig. 2) back to its normal position (solid lines in Fig. 2). The package N has been cleared off the rollers 221, so that other packages can follow, but the package N is still held horizontal by the tipper P, with the pallet rails L against the rollers 241.

It should now be stated that, while single-packs E and E, are being united into a single self-palletized package N, new single packs E are being stacked in a stacker and moved into an accumulator. However, to the next two packs the lower cap sheet H may or may not be added at the accumulator, depending on the pack desired, and the upper cap sheet K may or may not be later added at the press I, depending on the pack. Also, no pallet strips L are applied then. However, each of these second series of single packs is baled, preferably, by a single strip I, using bumper strips M to protect the edges, as before, to form a second group of two packages R (not shown) and S that are not unitized into a single package, because it is not necessary. They will soon rest on top of the unitized package N for movement therewith as a single unit, just as well as if they were completely unitized together. 7

The second series of baled (but unpalletized) packages R and S are then moved down onto the rollers 221, and the forward package R moves into contact with the stop 222, moving the switch 223. However, this time, something ditferent happens, because the first package N, upon engagement with the vertical portion 240 of the tipper P, closed a bypass switch 255 which will operate to hold the relay 243 closed (after its actuation by the switch 223), even when the switch 252 is open. Therefore, the disengagement of the cam 250 from the roller 251 will not cause the de-energization of the solenoid 244.

As a result, the cylinder 245 continues to be filled with fluid and its piston 247 continues to be pulled in, even after the packages R and S have been lifted from the conveyor 0 and have slid against the palletized package N, until the frame 231 has tipped more than 90 to the other dotted-line position in Fig. 2 (counterclockwise rotation as in Fig. 2); in fact, until pressure is released from the switch 255, which happens only when the package N and packages R and S roll off the tipping rollers 241. At this time, the packages N, R and S have been turned over 90 and have rolled to the position shown in lower broken lines in Fig. 2; and at this time the entire assembly of cartons rests on the pallets L. When they finally slide over the rollers 241, the pallets'L are deposited on the ground or, better, on gravity rollers 256 on an inclined frame 257, along which they roll by gravity, to a desired loading point. There, a forklift truck may lift up each package assembly of N, R and S and either stack them further, carry' them to atruck, carry them to a warehouse and stack them atop each other, or make any other desired disposition -of them.

It may be noted'that the device is not limited to producing a two-layer unit. I A one-layer unit may be produced by using the switch 255 only as a return switch after full tipping. Or, by obvious electrical circuitry the tipping device may accumulate several layers before tipping over Manual control may nullify the bypass effect of the switch 255 until the last desired layer is on the frame 230. Of course, the size of the tipper may be varied to handle the desired number of layers of any size of carton. The two-layer unit is a very good one for many uses, but one-layer, three-layer, four-layer, etc. units have been used very successfully. Two-layer units have also been alternated with three-layer units, and three-layer and four-layer units have been alternated. The basic device as described may be altered by means familiar to the man in the art to accomplish these results.

The electric circuit (Fig. 4)

Most of the operating elements of the circuit have already been discussed in preceding sections, but it remains to trace the preferred circuitry. Preferablyflthe power is supplied by a source 260 of 220-volt B-phase current, which is connected to the motor 141, by leads 262, 263 and 264, The connections between these leads and the motor is made through normally open relay and this relay is actuated by a master-control circuit whose description will form the body of this section.

The circuit is provided with a master-control relay 270 which is energized upon closure of a master-control switch 271 and which obtains its power by tapping across leads 263 and 264, via leads 273 and 274. Unless the master-control switch 271 is closed, the master-control relay 270 is open and nothing in the circuit will operate. All the remaining circuits are in series with the main relay 270. Most of them are in parallel with each other across main power lines 275 and 276, but direct control over the motor 141 is maintained by leads 277 and 278 which are also in series with the master-control relay 270. (A) Raising and lowering the rollers 142.The circuit for the solenoid 168 and switch 169 will now be described. The solenoid 168 is connected to the lead 391 by a lead 408 and by a lead 409 to one side of a relay 410, and from there by a lead 411, a normally closed, relay-opened contact 412, and a lead 413 to the lead 387. The other side of the relay 410 is connected by a lead 414 to the leads 391 and 390. The switch 169, normally closed, is connected to the power line 276 by a lead 415 and by a lead 416 to the normally open contact 417 of a switch 418 operated by the relay 410.

When the relay 418 is energized, power from line 276 passes through leads 395 and 394, switch 223, lead 3923, switch 151, lead 392, switch 386, pole 385, leads 381 and 389, switch 388, lead 387, lead 413, switch 412 and lead 411, and through the relay 410 and leads 414 and 391 to the power line 275. The relay 410 is then energized and closes the normally open switch 418 against the contact 417. Therefore, until the switch 151 opens, the relay 410 continues to hold by the circuit from line 275 through leads 391 and 414, the relay 410, switch 418, contact 417, lead 416, switch 169, and lead 415 to the other power line 276.

When the switch 169 is opened, the relay 410 will be de-energized, the switch 418 moving away from the contact to its opposite position, which is then an open circuit.

The power circuit holding the solenoid 168 energized during energization of the relay 410 is from power line 275 through leads 391 and 408, solenoid 168, switch 418, contact 417, lead 416, switch 169, and lead 415 to the power line 276. When the solenoid 168 is energized, its valve 168a raises the rollers 142 and keeps them up. Again, opening the switch 169 de-energizes the solenoid 168 and lowers the rollers 142. Closing the switch 169 is ineffective until the switch 388 is again closed by the relay 140.

(B) The circuit for opening and closing the stop gate 150.--One side of the switch 200 is connected by lead 420 to lead 393. The other side is connected by lead 7 421, to one side of the relay 201 and by lead 422 to one side of the solenoid 202. Lead 423 from the other side of the relay 2111' and lead 424 from the other 'side of the solenoid 202 are connected by lead 425 to the power line 275. A normally open relay-controlled switch 426 is connected to the lead 421, being normally held away from a contact 427 which, in turn, is connected by a lead 428 to the lead 393.

When the switch 260 is closed, power from line 276 passes through leads 395 and 394, switch 223, lead 393, lead 420, switch 200, lead 421, relay 201, and leads 423 and 425 to the power line 275, energizing the relay 201. At the same time, the solenoid 202 is energized by the parallel circuit leads 422 and 424. Upon energization, the relay 201 closes the switch 426 against the contact and from then on, so long as the relay 201 remains energized, power passes directly from lead 276 through leads 395 and 394, switch 223, leads 393 and 428, switch 426, relay 2111, and leads 423 and 425 to power line 275. The solenoid 202 is retained energized by the parallel circuit from the switch 426, through leads 421 and 422, the solenoid 292 and lead 424 to the lead 425. The solenoids valve 242a operates the cylinder 204 that opens the gate 150 and holds it open until the switch 223 is opened by the package N. When the switch 223 is opened, the relay 201 and solenoid 202 are de-energized, and since the switch 200 is of the type that remains closed only instantaneously, the relay 1 will not be re-energized when the switch 223 again closes.

(C) The circuit for moving the baled package N from the press I to the tip-over unit P.A normally open manually controlled switch 215, is used to energize the motor 141 to move the package N from the press I to the unloader P. The manual control switch 215 is preferably supplied with two switch elements 440 and 441. Element 440 bridges leads 442 and 443, while the element 441 bridges the leads 444 and 445. The leads 443 and 445 are both connected to the lead '387. The lead 442 is connected to the lead 389, and the lead 444 is connected to the lead 393;

Closure of the switch 215 causes the two switches 440 and 441 to bridge their respective leads. The motor 141 then operates through the circuit from the line 275, lead 403, the motor relay 140, lead 402, switch 40 1, leads 400, 387 and 445, switch element 4411, leads 444 and 393, switch 223, and leads 394 and 395, to the power line 276. Thus, the relay 140 is energized and the motor 141 will run. Once the relay 140 is energized, the switch 388 is closed; therefore, uponrelease of the switch 215, the motor 141 will run by the circuit from line 275 through lead 403, relay 140, lead 4112, switch 401, leads 450 and 387, switch 388, leads 389 and 381, pole 385, switch 386, lead 392, switch151, lead 393, switch 223, and leads 394 and 395 to the power line 276. Thus, the motor 141 remains running until the circuit is broken by the package N opening the switch 223, which stops the motor 141 and de-energizes the relay 140, breaking the switch 388.

The upper switch portion 440 is used to insure that the rollers 142 will be in their raised position. This happens because the strapping section switch 169 is closed. Therefore, current passes from the line 276 through leads 395 and 394, switch 223, leads 393 and 444, switch 441, leads 445, 387 and 443, switch 440, leads 442 and 389, switch 388, leads 387 and 413, switch 412, lead 411, relay 411 and leads 414 and 391 to the line 275, thereby energizing the relay 410. This causes energization of the solenoid 168 through the circuit of line 275, leads 391 and 403, solenoid 168, lead 409, switch 418, contact 417, lead 416, switch 169, and lead 415 to the line 276. The relay 411} is retained energized after the switch 215 is opened by the circuit parallel to the solenoid 168,, as .described before. '(D) The tip-over circuit.--The tip-over circuit is inoperative so long'as the switch 223 is in its normal position, as shown in Fig. 13; but this switch 223 is moved when the package N engages it against a contact 450. The contact 450 is connected through lead 451 to a normallyopen contact 452 which is closedby a switch 453 upon energization of the relay 243. Similarly, the lead 395 is, itself, connected by a line 454 to the normally open switch 453, and to another normally openswitch 455, both operated by the relay 243. The normally open contact 456 for the switch 455 is connected by a lead 467 to the solenoid 244 which, in turn, is connected by a lead 458 and lead 425 to the power line 275.

The contact 450 is also connected by lead 468 to one side of the normally closed switch 252 and by lead 461 to one side of the normally open by-pass switch 255. A lead 463 from the opposite side of the normally closed switch 252 and a lead 464 from the other side of the switch 255 are connected by a lead 465 to one side of the relay 243. The other side of the relay 243 is connected by the lead 465 to the lead 425- and thence to the line 275.

Thus, when the switch 223 is moved against contact 450, current passes from line 276 through leads 395 and 394, switch 223, contact 450, lead 450, switch 252, leads 463 and 465, relay 243, and leads 466 and 425 to power line 275, energizing the relay 243. This causes the switches 453 and 455 to close, sending current from line 276 through leads 395 and 454, switch 453, contact 452, leads 451 and 461 ,'switch 252, leads 463 and 465, the relay 24-3, and leads 466 and 425 to the line 275, thereby holding the relay 243 closed upon release of the switch 223. At the same time, power from line 276 through leads 395 and 454, passes through the switch 455, contact 456, lead 467, solenoid 244, and leads 458 and 425 to the power line 275, actuating the tipping cylinder 245 through the valve 244a. Tipping continues until, on the first package N, switch 252 is opened by the cam 250 as described heretofore. Opening the switch 252 de-energizes the relay 243, therefore, shuts 011 the solenoid 244, and valve 244a reverses its ports,

As the second tipping begins, the switch 255 is already closed by the package N, but since that occurred after the relay 243 was de-ener'gized and, since the switch 223 was then also back in its normal position, there was no reene'rgization when the switch 255 closed. When the switch 223 again opens, the relay 243 is energized in the same manner as before, but it is kept energized after the switch 252 is opened by current passing through the switch 255, which remains closed until the bundle leaves the tipping unit itself, which releases the switch 255 and de-energizes the relay 243 and the solenoid 244;

the valve 244a then reverses its ports, and the tipping frame 230 returns to normal position.

Operation The operator starts the device by closing the master control switch 271 which energizes the master-control relay 270.

When stacks E and E move to the press I, the motor 141 causes the rollers 142in the press I to take over and move the packages 'E and E in the press I until the packages reach the stop-gate 151) and open the switch 151, which stops both motors 123 and 141. When the packages E and E engage the stop gate they still have sufiicient momentum to cause them to straighten up, in case they are not vertical.

There are usually two operators at the press I, one on each side. One of them is the same one who puts in the cap sheet H at the accumulator G, and he now puts in the upper cap sheet K. The, other operator usually helps put the lower bumper strips N into the grooves provided by the members 190 and then, if the stacks E and E are in order, he pushes the lever 186 to the left causing the hydraulic pump 185 to pump fluid into the cylinders 181) and 181 and, thereby, cause the platen to begin descending. However, closure of the lever 186 to the left also opens the switch 169, which de- Q energizes the relay 410 and solenoid 168; so the cylinder 164 retracts its piston 165 and lowers the frame 160 and its rollers 142 below the level of the bed 156 before the platen 170 engages the upper cap sheet K or the top of the box stack. The platen 170 continues to descend and the operator holds the lever 186 to the left until the desired compression has been achieved, which he may notice on a gauge (not shown) or which may be automatically determined by the relief valve 187.

When the press I has been lowered party way it is usually stopped for insertion of the upper bumper strip M into the groove provided at 192. With both bumper strips M in position, the stack is compressed fully by the platen 170. Then the straps J from the reel 196 are passed around the stacks-usually through the upper channels 193 over the bumper strips Mdown along the opposite side (over the pallet boards L, which are now inserted if used) and under the lower bumpers M through the botom channels 191, and then up the right-hand side, as shown in Fig. 8, to the actual strapping device 198 where the ends are brought together in the strapping machine. The operator then energizes the strapping machine, which usually has its own motor as made by the manufacturer, and it tightens the band I very tightly around the package. Meanwhile, the other operator is inserting the lower cap sheet H beneath another stack in the accumulator G.

When the baling has been completed, which takes only about 40 seconds, the operator moves the lever 186 to the right and the hydraulic pump bleeds fluid from one side of the cylinders 180, 181 and sends it into the other side, lifting the platen 170. The platen 170, in both directions, is guided by the rack-and-pinion structure.

When the platen 170 lifts, it engages the switch 200, energizing the cylinder 204 which opens the stop gate 150. The operator then presses the manual switch 215 to energize the motor 141 and start the bundle N moving out of the press I. The self-palletized package N moves on to the conveyor and moves by gravity along over the rollers 221 until it engages the stop222, automatically throwing the switch 223. The switch 223 then energizes the relay 243, which energizes the solenoid 244 to begin tipping the unloader P. The unloader P lifts the package N off the rollers 220 onto its finger rollers 237, on which it begins to roll, and it rolls down the incline provided by the tipped unloader P, onto the rollers 235 and along them until it engages the rollers 241 sup ported by the vertical portions of the frame 230. At that time, the package N closes the switch 255, but it is by then too late to do anything, because by then the cam 250 has left its roller 251 and opened the switch 252, which de-energizes the relay 243 and solenoid 244 and causes the unloader P to return to its horizontal position.

A second series of two bundles R and S, handled in the same way in the stacker, have meantime been passed into the accumulator G, where no cap sheet was applied and, from there, into the press I where, again, no cap sheet was applied nor was any pallet board applied. However, bumpers M were inserted as before, and a single strap J was passed around each bundle, with the bumpers M protecting the corners of the bundles R and S. Bundles R and S are then moved forward as before, into the tipping device P, and against the switch 223.

Engagement of the switch 223 again causes the unloader P to begin tipping; but, this time, due to closure of the switch 255 by the bundle N, the tipper not only will lift the packages R and S ed the rollers 221 and roll them down against the package N, but will continue to tip until it is past more than 90, and the pallets L are able to slide along over the rollers 241 and drop down to the conveyor Q where they slide over the gravity rollers 256 to the desired loading point. Thus, the package ends up by having a baled, unitized package N with cap sheets H and K and pallet boards L at the lower level, with the pallet boards L resting on the floor, and with two baled unpalletized packages R and S resting side-by-sid'e on top of the self-palletized package N. Of course, as mentioned before, the unit may comprise more or fewer layers.

To those skilled in the art to which this invention relates, many changes in construction and widelydiifering embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein'are purely illustrative and are not intended to be in any sense limiting.

What is claimed is:

l. A tipping device for tipping bales of cartons and the like off a roller conveyor, comprising: an L-shaped frame with normally horizontal portions extending across said roller conveyor below the level of the rollers and having a normally vertical portion, both horizontal and vertical portions being roller mounted, said frame being rotatably mounted; a stop member at the end of said roller conveyor for stopping a said bale opposite said tipping device and over a portion of its horizontal portion; means for rotating said tipping device; means for activating said means for rotating upon engagement of a first said bale at said stop member; first means for stopping rotation of said tipping device and returning it to horizontal position after said first bale has been lifted olf said roller conveyor and moved along by gravity over said normally horizontal portion beyond said roller conveyor toward engagement with said normally vertical portion; and second means for stopping rotation, said second means nullifying said first means and permitting rotation so long as said second means is engaged by a said bale, said second means being engaged by a said bale when said bale is in a certain position along said normally horizontal portion, so that when said second means is engaged and a later bale, similar in size and shape to said first bale, actuates said means for rotating said tipping device, said first means for stopping rotation is nullified and said tipping machine not only lifts said later bale off said roller conveyor but also tips more than to unload its burden of all said bales.

I 2. A tipping device for rotating bales of cartons in plural layers, said device comprising: a gravity conveyor for said bales; an L-shaped frame having normally horizontal portions extending across said gravity conveyor slightly below its upper surface, and having 'a normally vertical portion, both horizontal and vertical portions supporting conveyor rollers whose axes lie Parallel to the axis of said gravity conveyor, said L-shaped frame being rotatably mounted; a stop member at the end of said gravity conveyor for stopping a said bale at a location beside said L-shaped frame and over part of its horizontal portion; rotating means for said L-shaped frame; means for activating said rotating means upon engagement of a bale at said stop member; first means for stopping rotation of said L-shaped frame and returning it to horizontal position after said bale has been lifted olf said gravity conveyor and moved along said normally horizontal portion, said bale continuing to move until moving into engagement with said normally vertical portion; and second means for stopping rotation engaged when said bale engages said normally vertical portion, said second means nullifying said first means and permitting rotation so long as said second means is engaged by a said bale, so that when a succeeding layer of bales, similar in size and shape to the first said bale is advanced over said gravity feed and actuates said rotating means, said first means for stopping rotation is nullified and said L-shaped frame tips more than 90 to unload its burden of all said bales.

3. An unloading device for bales of cartons and the like, comprising: a gravity conveyor for said bales, having a series of rollers on a frame; a tipping device having normally horizontal arms extending across said gravity conveyor normally below and between said rollers and 11 supporting its own rollers on said arms and having a normally vertical back also provided with rollers; said tipping device being rotatably mounted; a stop member stopping rotation of said tipping device and returning it to horizontal position after rotation through a predetermined angle suflicient to lift a first group of said bales off said gravity conveyor and to cause it to move along said arms and against said back; and a second normally open stop switch on said back, closed by said bale for bypassing said first stop switchas long as said second stop switch is engaged by said bales; whereby when a second group of bales, similar in size and shape to the first group of bales, is moved along said gravity conveyor to actuate said switch for activating-said rotating'means, said first stop. switch is nullified, said tipping machine tips more than 90 to lift said second group of bales on'said first group of bales, and then unloads both said groups of bales.

References Cited in the file of this patent UNITED STATES PATENTS 1,498,732 Jauch Tune 24, 1924 1,632,204 Threefoot June 14, 1927 1,933,147 Paxton Oct. 31, 1933 2,038,758 Paxton Apr. 28, 1936 FOREIGN PATENTS 148,895 Sweden Feb. 15, 1955 

